The Things You Don't Know About Me
by maxthegee
Summary: Castle discovers some things in his partner's life that he didn't know before. Set in S4 Caskett
1. Chapter 1

He knocked at her apartment door, patiently waiting for her to open. When nothing happened he knocked again.

„Coming" shoutet Kate Beckett from inside the aparmtent and only five seconds later opened the door.

„Hey Castle, what do you want?"

„I know who the killer is!" Castle answered excited and moved to enter the apartment but Beckett blocked the door.

„Listen Castle, right now is not a good time. Call Ryan and Esposito to pick whoever the killer is up."

Castle noticed only then that she looked really tired.

„Ka-" he started but was interrupted by a cry from inside. He threw a puzzled look at her. She sighed and opened the door wider to let him in.

The first thing he noticed were the toys that were spraweled all over the couch and floor, the second thing was the crying child sitting in between them.

Kate went over to pick him up and calm him down.

„Hey Johnny, can you stop crying to say 'hi' to mommy's friend?" She asked him silently.

Castle still stood in the doorway, shocked, staring at the boy in Beckett's arms. Johnny shook his head stubbornly and burried his face in his mother's neck.

„I'm sorry, he's been sick the whole day. Should probably sleep anway..." Kate trailed off with a knowing smirk. Johnny's head shot up.

„I'm not going to bed, Momma"

„Ok, then say 'hi' to Castle."

He sighed loudly and then turned in his mother's arms to look at Castle.

„Hi, I'm Johnny. You're Castle, right? Momma talks loads about you."

Castle had a huge grin on his face.

„Does she now? Beckett, I didn't know you liked me that much."

„Who says I talk about you becaus I like you? I always complain because you're so annoying!" She defended herself but the damage was already done. Castle couldn't stop grinning.

A/N: This is my first story ever and I hope you like it :) The chapters will be longer soon, this is just the beginning :) Hope you enjoyed it. **Also sorry for any mistakes, English is not my first language.**


	2. Chapter 2

**A/N: Thank you so much for the reviews.**

 **I edited a bit of the last chapter and I also wanted to clear some things up.**

 **Johnny is five years old, how all the things happened will be either explained in this chapter or the next.**

 **This story is going to include LGBT themes, if you don't like that you shouldn't read this** **.**

 **Sorry it took so long to update, I originally planned to update on Monday, but I forgot to safe the document and everything I had written before was deleted. I also needed to do a completely new outline because there was a huge plothole which I kinda fixed now.**

 **Anyway on with the story**

While Kate put Johnny to bed Castle called Ryan to tell him who the killer was. When Kate came back Castle was sitting on her couch, surrounded by Johnny's toys.

"Care to explain?" he asked silently, as not to wake Johnny.

Kate sighed silently and walked over to sit down next to him, tucking one leg under the other and facing Castle.

"Before I came to homicide I was undercover. It was my job to become friends with Jaden Warrenton, a gang leader. It worked all really well, nobody suspected I was a cop.  
I started a relationship with Jaden's best friend, Samuel Hunter. It wasn't supposed to happen, actually it was forbidden - still is - but me and Sam just clicked and we got together. Sam had a kid before I got there, he was still a baby, maybe a few months old. His mother had left him with Sam, I don't really remember why.  
Everything was fine, I lived with Sam and Johnny for a few months, had contact with my people and was getting more and more information from Warrenton.  
But my cover blew, I don't know who it was, but he found out that I was a cop. He came to Sam's apartment, started shooting. Nothing happened to me or Johnny, but Sam was hit, immediately died. I was the closest thing Johnny had to a mother, so I took him in."

Kate stared in the distance. To Castle, she seemed completely closed off, even more than usual. But he couldn't help, but to ask more questions.

"Why did you never tell anyone? I mean, I'm guessing your father knew and Montgomery? What about Gates? Lanie, Ryan, Espo? Did they know?"

Kate silently shook her head.

"No. It's really dangerous to just go and leave a gang you've been part of for several months, even more so as a cop. They told me I could keep him but for his protection and my own I had to stay quiet about it. If anything about a cop who had the kid of a gang member came out it could have been dangerous.

My dad knows. He takes care of Johnny while I'm at work. Montgomery knew, too, same as Gates, but that's only because it's stated in my files."

"Can I ask you more questions about this?" Castle asked wearily "or is it better tomorrow?"

"No, no go ahead." Kate told him, surprised that he didn't seem mad at her for keeping such a big thing from him.

"I was here so often, how did I never notice? What happened when your apartment blew up two years ago, you were here alone, right?"

"Yeah, to be honest, he's more often at my Dad's than here, but I'm planning to change that. I talked to Gates. I have some vacation days and I'll use them this summer to spend more time with him. That was long overdue."

Castle nodded his head silently and started to get up, when another question popped into his head.

"Kate?"

When Beckett had her full attention back on him he kept talking.

"Can I, can I meet him? I mean properly meet him, not just 'hi' and that was it. I want to know what he's like..." he trailed off, afraid she might say no, but to his surprise she smiled softly.

"Sure, Castle, I think he'd love that. Actually he's not going to school tomorrow, since he's sick, I know it's alot to ask on such short notice but my father's not in town and I don't have anyone else to ask, so could yo-"

"Babysit him?" he asked, the joy already shining in his eyes as a smile spread over face.

"Yeah, I can do that" he explained excited. "When do you want me here?"

Kate thought for a second.

"I'm on call tomorrow, so whenever a body drops, I'll call you, if that is alright."

"That's more than alright, this is great!" he almost shouted. Kate shot him a warning look and he calmed down immediately, but she could still see the sparkle of excitement in his eyes.

"I can't wait until tomorrow."

He grinned at her, stood up and walked to her door, closing it softly behind him.

 **A/N I kinda stole the undercover idea from when Ryan was undercover, but it is a bit different so it's okay, I guess. Hope you enjoyed this chapter :)**


	3. Chapter 3

**A/N: Hey guys, so sorry this took so long. I had a lay out of the story, than decided I didn't like it, wrote it again, didn't like it and deleted it all. I have some things I definitley want to happen, but I'm not sure when and how I'll get there. I'm just going to give it a go, but I'm not sure how much I'll be able to write until I hit a point where I don't know how to continue.**

 **Anyways Happy Christmas, Hanukkah, and Kwanzaa. If you don't celebrate anything I hope you have a happy normal week ;-)**

 **Hope you enjoy :)**

* * *

Kate woke up from someone jumping on the bed and screaming 'Momma' over and over. She opened her eyes and grabbed Johnny pulling him down next to her.

"Hi, little kangaroo, you don't seem sick to me at all." She said with a laugh.

„Momma, I'm not little!" The boy protested.

"Of course not baby, you're the biggest person I've ever met." She grinned at him while he pouted.

"But you're bigger than me. And Papa, too."

"Really? I didn't notice." Kate stood up slowly, her son wrapped around her neck.

"Wanna eat breakfast?" She asked. The grin on Johnny's face was enough of an answer and she made her way into the kitchen.

"What do you want, baby?" She sat him down on one of the chairs that stood arounf the small table in the even smaller kitchen. Affording a decent sized apartment in New York on Cop salary was hard enough as it was. With a kid added to the mix it was nearly impossible. Thank God her father was somewhat rich and paid some of the rent.

"Hmmmm... Pancakes!" Johnny exclaimed with a huge smile on his face.

"OK, wanna help make the batter?" She hadn't even finished the sentence and Johnny was already standing in front of her, waiting for his mom to pick him up on the counter.

"You can stir it, okay?"

Johnny nodded, focused on the task. Sometimes it surprised Kate how her son could be so hyper and excited in one moment and in the next completely focused and concentrated. She watched Johnny stirring, when suddenly there was a knock at the door.

She looked at the clock that hang on the kitchen wall. 10 am. Who on earth would be here at that time on a work day? She hadn't forgotten a meeting with her dad, had she?

"You keep stirring, I'll be right back." She kissed Johnny's head, who barley noticed it, still stirring the batter.

Beckett walked through her apartment to the door and opened it. Standing in front of her was no other than Richard Castle with a huge smile on his face.

"Castle? What are you doing here?" She asked perplexed.

"I couldn't wait for a body to drop."

"And you thought, that it would be alright to just come bursting in my apartment, while I might be asleep?" She asked, her voice becoming a bit higher.

Castle stared at her, the happy look from before exchanged by a slightly horrified one.

"I-i just thought, since, you know, you never sleep later than seven that m-maybe I could come over. If it's not a good time, I'll leave again."

He looked so miserable, Beckett almost felt sorry for messing with him. Almost.

When she started laughing, Castle looked even more terrified than before, which caused her to laugh even more. God, what was wrong with her?

"Momma?" came Johnny's voice from the kitchen.

"I'll be right there, baby." She called back. "Come on in, we're making pancakes" She said with a smile to Castle and opened the door wider to let him in.

She led him to the kitchen, where Johnny still sat on the counter, stirring the batter.

Kate walked over to him. "That's alright, baby, thank you." She said, while taking the spoon from Johnny and helping him from the counter. "Castle, can you get some plates, please?"

"Uh, sure, if you tell me where I can find them." he said with a small chuckle.

Instead of Beckett answering him he felt a small hand tug at his shirt. "I'll show you."

Castle looked down to see Johnny, still tugging on his shirt, and pulling him to the cabinet on the far right side of the kitchen. Castle got the plates out and set them on the table, while Johnny got the silverwear. They sat down and Castle immediately engaged Johnny in a heated discussion over which Avenger was the best.

15 minutes later Kate set a plate with multicolored and weirldy shaped pancakes on the table.

Castle eyed them carefully and shot her a confused look. "Beckett, what exactley is that supposed to be?" he asked skeptically.

"The pancakes? Nothing in particular, Johnny just liked them in different colors." She said, looking at Johnny, who had already taken one and was half way done with it. "Don't eat to fast, John, or you'll get sick again." She scolded him soflty. Johnny just grinned at her mischievously, but slowed down a bit.

"Dig in, Castle, we can't sit here all day."


End file.
